Patients with breast carcinoma and paraneoplastic ataxia, frequently in combination with opsoclonus, often have antibodies to the Ri-antigen(s) [23], which targets the RNA-interacting region of (neuro-oncological ventral antigen-1) (NOVA-1), a neuron-specific RNA-binding protein that is differentially expressed in the diencephalon, brainstem and cerebellum [24]. Here, NOVA1 is linked to Opsoclonus.